KR20040060107A - In-Plane Switching mode Liquid Crystal Display Device - Google Patents

Abstract

PURPOSE: An IPS(In Plane Switching) mode LCD(Liquid Crystal Display) is provided to form a pattern spacer on a data line and the region of an array substrate corresponding to the data line, thereby preventing backlight phenomenon from generating. CONSTITUTION: A black matrix(8) and a sub color filter(6) are formed at a color filter substrate(5). Subpixels are arranged to an array substrate(22) as a matrix type. A liquid crystal(20) is injected between the color filter substrate(5) and the array substrate(22) and sealed by sealant coated on the edge of the substrate. A spacer(40) is formed between the color filter substrate(5) and the array substrate(22) in order to form a space for injecting the liquid crystal(20). A forming region of the pattern spacer(40) is the region positioning on the array substrate(22) including data lines(15,15') and common electrodes(54a,54a') adjacent to the data lines(15,15').

Description

Transverse electric field type liquid crystal display device {In-Plane Switching mode Liquid Crystal Display Device}

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a liquid crystal display device, and more particularly, to a transverse electric field type liquid crystal display device in which a pattern spacer is formed in a region on an array substrate corresponding to a data line and a common electrode adjacent to the data line.

In general, the driving principle of the liquid crystal display device uses the optical anisotropy and polarization of the liquid crystal. Since the liquid crystal is thin and long in structure, the liquid crystal has directivity in the arrangement of molecules, and the direction of the molecular arrangement can be controlled by artificially applying an electric field to the liquid crystal.

Accordingly, if the molecular arrangement direction of the liquid crystal is arbitrarily adjusted, the molecular arrangement of the liquid crystal is changed, and light polarized by optical anisotropy may be arbitrarily modulated to express image information.

One of the liquid crystal display devices currently used is a twisted nematic (TN) type liquid crystal display device. The twisted nematic method is a method of driving the liquid crystal director by installing electrodes on two substrates, arranging the liquid crystal directors to be twisted by 90 °, and then applying a voltage to the electrodes.

However, the TN (twisted nematic mode) liquid crystal display device has a big disadvantage that the viewing angle is narrow.

Recently, researches on liquid crystal display devices employing various new methods have been actively conducted to solve the narrow viewing angle problem. In this method, an in-plane switching mode (IPS) or OCB method (Optically Compensated Birefringence mode).

Among these, the transverse electric field type liquid crystal display device has two electrodes formed on the same substrate in order to rotate the liquid crystal molecules in a horizontal state with respect to the substrate, and a voltage is applied between the two electrodes so as to be horizontal with respect to the substrate. Generate an electric field in the direction. In other words, the long axis of the liquid crystal molecules does not stand on the substrate.

For this reason, the change in the birefringence of the liquid crystal in the visual direction is small, so that the viewing angle characteristic is much superior to the conventional TN type liquid crystal display device.

1 is a plan view showing a part of an array substrate for a transverse electric field type liquid crystal display device.

Referring to FIG. 1, the array substrate has a plurality of gate lines 13 and a common line 54 formed in parallel in a horizontal direction, and a plurality of data lines 15 in the vertical direction form the gate lines 13. And perpendicular to the common line 54.

As such, the subpixel 10 in the array substrate is defined as a portion surrounded by the gate line 13, the common line 54, and the data lines 15 and 15 ′.

In addition, a gate electrode 31 is formed at one side of the gate line 13, and a source electrode 33 is predetermined to the gate electrode 31 at the data line 15 near the gate electrode 31. The drain electrode 35 is formed at a position overlapping with the source electrode 33 and having a gap, thereby forming a thin film transistor region T in the sub-pixel 10.

In addition, the common line 54 is formed with a plurality of common electrodes 54a branched from the common line 54. A lead wire 37 is connected to the drain electrode 35. A plurality of pixel electrodes 37a branched at 37 are formed.

Here, the common electrode 54a and the pixel electrode 37a are staggered from each other, and the image display area of the subpixel 10 is formed by the plurality of staggered common electrodes 54a and the pixel electrode 37a. This is to be formed.

The common electrode 54a configured in the sub pixel 10 is in a state where a common voltage input from the common line 54 is always applied, and the pixel electrode 37a is applied to the gate electrode 31. According to the level of the gate voltage, various levels of image signals are applied through the data line 15.

Accordingly, the lateral electric field is distributed by the voltages applied to the pixel electrodes 37a and the common electrode 54a, which are adjacent to each other, and the degree of arrangement of the liquid crystals varies according to the intensity of the electric field, thereby displaying an image.

In this way, a region in which the lateral electric field is distributed by the pixel electrode 37a and the common electrode 54a to display an image is called a block 39, and a plurality of blocks 39 are formed in the sub-pixel 10. In general, as shown in FIG. 1, a four-block type in which four blocks 39 exist in one sub-pixel 10 is commonly used.

2 is a cross-sectional view of a conventional transverse electric field type liquid crystal display device including a cross section of a specific portion A-A 'of FIG. 1.

Referring to FIG. 2, the conventional transverse electric field type liquid crystal display device includes a color filter substrate 5 having a black matrix 8 and a sub color filter 6 arranged therein, and the subpixels illustrated in FIG. 1 arranged in a matrix form. And a liquid crystal as described above are inserted between the color filter substrate 5 and the array substrate 22, and bonded by a sealant (not shown) applied to the edge of the substrate. In addition, a spacer (not shown) is scattered to provide a space in which the liquid crystal 20 can be injected between the color filter substrate 5 and the array substrate 22.

1 and 2, an image display area of the subpixel 10 formed on the array substrate 5, that is, an area through which light is not transmitted except for the four blocks 39, is thus obtained. The black matrix 8 of the color filter substrate 5 is formed in a region other than the region of the block 39 to block unnecessary light.

However, the data lines 15 and 15 'and the common electrodes 54a and 54a' adjacent to the data lines 15 and 15 'do not correspond to the block 39 region, and thus are black as shown in FIG. 2. If the area is blocked by the black matrix 8, the light leakage defect occurs when misalignment of the color filter substrate and the array substrate 5 and 22 occurs. Done. In particular, when the substrate size increases, the misalignment degree of the color filter substrate and the array substrate 5 and 22 becomes more severe, so that the width of the black matrix 8 of the color filter substrate 5 should be large. This results in a reduction of the aperture ratio. In addition, a light leakage phenomenon may occur due to the refraction effect of light in this portion.

Due to the light leakage phenomenon, in the case of a horizontal electric field type liquid crystal display device having a conventional structure, there is a disadvantage in that spots appear on the display screen of the liquid crystal display device due to the light leakage phenomenon.

The present invention forms a pattern spacer in a region on an array substrate corresponding to a data line and the data line or between a common electrode adjacent to the data line, thereby preventing a liquid leakage in the region, thereby preventing a light leakage phenomenon. It is an object of the present invention to provide a liquid crystal display device.

1 is a plan view showing a part of an array substrate for a transverse electric field type liquid crystal display device;

2 is a cross-sectional view of a conventional transverse electric field type liquid crystal display device including a cross section of a specific portion A-A 'of FIG.

3A to 3D are cross-sectional views illustrating a method of forming a spacer of a liquid crystal display device.

4 is a cross-sectional view of a transverse electric field type liquid crystal display device according to an embodiment of the present invention.

5 is a cross-sectional view of a transverse electric field type liquid crystal display device according to another embodiment of the present invention.

<Explanation of symbols for the main parts of the drawings>

5: color filter substrate 6: sub color filter

8: black matrix 20: liquid crystal

15, 15 ': data line 39: block

54a, 54a ': common electrode 40, 50: pattern spacer

In order to achieve the above object, a transverse electric field type liquid crystal display according to the present invention includes an array substrate in which subpixels defined by a plurality of gate lines, a common line, and a data line are arranged in a matrix form, a black matrix and a sub matrix. And a liquid crystal layer interposed between the color filter substrate on which the color filter is formed, the spacer formed on the data line, and the array substrate and the color filter substrate.

In addition, the plurality of gate lines and the common line formed on the array substrate are formed parallel to each other in the horizontal direction, and the plurality of data lines are formed to cross the gate line and the common line in the longitudinal direction. .

The subpixel may include a thin film transistor, a plurality of common electrodes branched from the common line, and a plurality of pixel electrodes branched from a drawing wiring connected to the drain electrode of the thin film transistor. The pixel electrodes are characterized in that they are alternate with each other.

In addition, the spacer is formed of the photoresist layer and is patterned and formed in a region on an array substrate including the data line and the common electrode adjacent to the data line.

The black matrix may be formed in an area on a color filter substrate in which light passing through an area including an area between the data line and the common line adjacent to the data line is blocked.

In addition, the spacer is formed in a region on the array substrate corresponding to the data line and the common electrode adjacent to the data line, the liquid crystal is located in the upper region of the data line, the spacer is formed by separating the spacer around the liquid crystal. It features.

According to the present invention, the light leakage phenomenon is prevented to minimize the occurrence of unevenness on the display screen, and also the width of the black matrix formed on the color filter substrate is reduced to improve the aperture ratio.

Prior to the description of the transverse electric field type liquid crystal display device according to the present invention, a spacer inserted to form a predetermined space between the color filter substrate and the array substrate in the liquid crystal display device will be described.

The spacers are dispersed in order to maintain the cell gap uniformly, and there are kinds of spacers such as fibrous spacers, elastic ball spacers, and adhesive spacers. However, since the spacer particles are randomly scattered on the substrate, when the spacer is present in the effective pixel portion, there is a problem that the spacer is reflected or the incident light is scattered and the contrast of the liquid crystal panel is lowered.

In order to solve the above problem, it has been proposed to form a spacer by a method using a photolithography process. In this method, a photoresist film is applied to a substrate, ultraviolet rays are irradiated through a predetermined mask, and then developed to form a dot or stripe-shaped spacer. Since the spacers can be formed and the cell gap can be adjusted by the thickness of the photoresist film, the gap width can be easily adjusted and the precision is high. Referring to the process cross-sectional view of FIGS. 3A to 3D attached to the spacer forming method of the liquid crystal display device as follows.

3A to 3D are cross-sectional views illustrating a method of forming a spacer of a liquid crystal display device.

First, as shown in FIG. 3A, the photoresist film 2 is coated on a lower substrate, that is, an array substrate, by a spin-coating method or the like.

As shown in FIG. 3B, ultraviolet rays are selectively irradiated onto the photoresist film 2 using a mask (not shown) and then developed to form a pattern of the photoresist film 2.

Next, as shown in FIG. 3C, rubbing is performed on the lower glass substrate 1 on which the pattern of the photoresist film 2 is formed to have a desired orientation when the subsequent liquid crystal is filled.

Finally, as shown in FIG. 3D, the color filter substrate is bonded onto the array substrate on which the rubbing is performed.

Hereinafter, exemplary embodiments of the present invention will be described in detail with reference to the accompanying drawings. FIG. 4 is a cross-sectional view of a transverse electric field type liquid crystal display device according to an exemplary embodiment of the present invention.

4 is a cross-sectional view including a specific subpixel region of the array substrate, and the array substrate according to the present invention has the same configuration as the conventional array substrate shown in FIG. Therefore, the same reference numerals are used for the same components as in FIG. 1.

Referring to FIG. 4, a transverse electric field type liquid crystal display according to an exemplary embodiment of the present invention includes a color filter substrate 5 having a black matrix 8 and a sub color filter 6 formed therein, and the sub shown in FIG. 1. The pixel 10 is composed of an array substrate 22 arranged in a matrix form, and the liquid crystal 20 described above is inserted between the color filter substrate 5 and the array substrate 22 and applied to an edge of the substrate. Is bonded by a sealed sealant (not shown). In addition, a spacer 40 is formed between the color filter substrate 5 and the array substrate 22 to provide a space in which the liquid crystal 20 can be injected.

However, the spacer is formed as a pattern spacer 40 by the formation method shown in Fig. 3, and the formation region is formed of the data lines 15 and 15 'and the data lines 15 and 15'. And an area on the array substrate 22 including between adjacent common electrodes 54a and 54a '.

1 and 4, except for an image display area of the subpixel formed on the array substrate 22, that is, an area in which light is not transmitted except the area of the four blocks 39, the four blocks ( 39) The black matrix 8 of the color filter substrate 5 is formed in the regions other than the region to block unnecessary light.

In this case, as illustrated in FIG. 2, the data lines 15 and 15 ′ and the common electrodes 54 a and 54 a ′ adjacent to the data lines 15 and 15 ′ correspond to the area of the block 39. It is not covered by the black matrix (8), in this case, even if the black matrix (8) to block the area by the liquid crystal 20 formed between the color filter substrate 5 and the array substrate 22 The light of the lower backlight is refracted and transmitted to an area where the black matrix 8 is not formed, thereby causing a defect.

To overcome this, an embodiment of the present invention includes the data lines 15 and 15 'and the common electrodes 54a and 54a' adjacent to the data lines 15 and 15 'as shown in FIG. The pattern spacer 40 is formed in a region on the array substrate 22.

As such, the pattern spacer 40 is formed in an area on the array substrate 22 including the data lines 15 and 15 'and the common electrodes 54a and 54a' adjacent to the data lines 15 and 15 '. In this case, since the liquid crystal 20 cannot be positioned in the region, light of the lower backlight passing through the region is not automatically transmitted in the normally black mode. Therefore, even if the color filter substrate 5 and the array substrate 22 are misaligned, light leakage may be fundamentally blocked.

As a result, it is not necessary to increase the width of the black matrix 8 in order to minimize the light leakage as in the conventional case, thereby improving the aperture ratio of the screen display area.

5 is a cross-sectional view of a transverse electric field type liquid crystal display device according to another exemplary embodiment of the present invention.

5 is a cross-sectional view including a specific subpixel region of the array substrate, and the array substrate according to the present invention has the same configuration as the conventional array substrate shown in FIG. Therefore, the same reference numerals are used for the same components as in FIG. 1.

Referring to FIG. 5, the overall configuration is similar to that of FIG. 4, except that the formation positions of the pattern spacers 50 interposed between the array substrate 22 and the color filter substrate 5 are different. .

That is, another embodiment of the present invention shown in FIG. 5 is applicable to the case where the widths of the data lines 15 and 15 'arranged on the array substrate 22 are wide. 15, 15 ′ and the data lines 15 and 15 ′ and the common electrodes 54a and 54a ′ adjacent to the data lines 15 and 15 ′. That is, since the pattern spacer 50 is not formed in the upper regions of the data lines 15 and 15 ', the liquid crystal 20 may be located in the region. As a result, a liquid crystal is positioned in an upper region of the data line, and a spacer is formed around the liquid crystal. However, even in this case, even if light is emitted to the liquid crystal 20 positioned above the data lines 15 and 15 ′, the light leakage phenomenon does not occur because all are blocked by the black matrix 8.

As a result, as shown in FIG. 5, the patterned spacer 50 is disposed between the data lines 15 and 15 ′ and the common electrodes 54a and 54a ′ adjacent to the data lines 15 and 15 ′. When formed in the region on 22), since the liquid crystal 20 cannot be positioned in the region, light refraction does not occur since the refraction of light by the liquid crystal 20 does not occur.

Also in this case, since the width of the black matrix 8 does not need to be increased to minimize the light leakage phenomenon, the aperture ratio of the screen display area is improved.

According to the liquid crystal display device of the transverse electric field method according to the present invention as described above, to prevent light leakage phenomenon to minimize the occurrence of stains on the display screen, and also to reduce the width of the black matrix formed on the color filter substrate as a result There is an advantage of improving the aperture ratio.

Claims (8)

An array substrate in which a subpixel defined by a plurality of gate lines, a common line, and a data line is arranged in a matrix form; A color filter substrate on which a black matrix and a sub color filter are formed; A spacer formed on the data line; And a liquid crystal layer interposed between the array substrate and the color filter substrate. The method of claim 1, The plurality of gate lines and the common line formed on the array substrate are formed parallel to each other in the horizontal direction, the plurality of data lines are formed in the longitudinal direction to cross the gate line and the common line in the longitudinal direction Liquid crystal display device. The method of claim 1, The subpixel includes a thin film transistor, a plurality of common electrodes branched from the common line, and a plurality of pixel electrodes branched from a drawing wiring connected to the drain electrode of the thin film transistor, wherein the plurality of common electrodes and the pixel electrode The transverse electric field type liquid crystal display device is characterized in that the staggered configuration. The method of claim 1, And the spacer is formed of the photoresist film. The method of claim 1, And the spacer is patterned and formed in a region on the array substrate including the data line and the common electrode adjacent to the data line. The method according to any one of claims 1 to 3, And the black matrix is formed in a region on a color filter substrate from which light passing through a region including the data line and the common electrode adjacent to the data line on the array substrate is blocked. The method of claim 1, And the spacer is formed in a region on the array substrate corresponding to the data line and the common electrode adjacent to the data line. The method of claim 7, wherein The liquid crystal display of claim 1, wherein a liquid crystal is positioned in an upper region of the data line, and a spacer is formed around the liquid crystal.